Thanks for sharing those mappings :-) Maybe this is only applicable to Macs other than PBs, but I am able to map my F-keys. I had to type ^V and then the F-key to get it to map, but it works great. Part of my .vimrc now looks like this:

which just saves and runs the current file with perl. I'm using a MacMini with a USB keyboard, so I know it's probably not exactly the same. Have you tried pressing ^V before the F-key to map something, or am I just really fortunate?